Head and neck cancers are a major cause of morbidity and mortality worldwide. Head and neck cancers generally include a group of related cancers originating from the aerodigestive tract. Such cancers may involve the oral cavity, the lips, pharynx, larynx, nasal cavity, and paranasal sinuses. Head and neck cancers also may include cancers of the esophagus.
The incidence of the specific types of head and neck cancer vary greatly throughout the world. For example, although rare in other regions, there is a high incidence of nasopharyngeal carcinoma, a human squamous cell cancer, in Southeast Asia and North Africa. The majority of head and neck cancers are squamous cell carcinomas.
Treatment of head and neck cancer may involve surgery to remove the cancer or radiotherapy and/or chemotherapy to destroy the cancer cells. Radiotherapy or radiation therapy remains the primary treatment for head and neck cancer. Radiotherapy uses high-energy x-rays given as external beam radiotherapy or internal beam radiotherapy to kill cancer cells or to stop them from growing further. Although radiotherapy can affect both cancer cells and normal cells, normal cells are better able to resist or recover from the effects of the radiotherapy.
The area of treatment for head and neck cancer varies. For example, treatment may involve the back of the throat and/or the lymph glands in the neck. The treatment is planned carefully to ensure that the rays are targeted precisely onto the cancerous area, and to do as little harm as possible to the surrounding healthy tissues and minimize side effects such as dry mouth (xerostomia) and inflamed mucous membranes (mucositis). Other side effects from poorly directed radiation include dental decay (caries) and death of bone tissue (osteoradionecrosis).
If the patient can be accurately positioned for repeat sessions of radiotherapy, then side effects may be minimized. In each session, the patient should be disposed in a substantially identical position. This can be difficult to achieve because the patient's lower jaw and tongue tend to change position even when the head is held securely.
A conventional approach to keeping the affected area stable during treatment involves depressing the patient's tongue onto the floor of the patient's mouth using a mouthpiece molded from contoured wax. The mouthpiece helps minimize the movement of the patient's tongue and jaw during the radiation procedure. Wax mouthpieces are disadvantageous at least because they must be molded individually for each patient and may change shape depending on the storage temperature or the temperature inside the patient's mouth.
Therefore, a need exists in the art for an improved means for reducing movement or immobilizing the patient's tongue during radiation treatment.